1. Field of the Invention
The invention is related to testing of software and, in particular, to a method for bi-directional probing of software.
2. Description of the Related Art
Among developers of software, one of the most important requirements is for the software to be reliable. Reliability refers to the ability of a software to operate without failure for a specified amount of time in a specified environment. To ensure a sufficiently high level of reliability, software must be thoroughly tested and debugged prior to release. Usually, the entire software program as a whole is tested, as well as the individual functional components (e.g., function calls, subroutines) that make up the software program. Typically, test vectors are generated containing a series of values for the variables that are required by the software and/or one or more functional components thereof. The variable values are chosen to represent various types of usage conditions and environments in which the software is intended to be run. The test vectors are then applied to the software and/or the one or more functional components thereof, and the variable values are observed and recorded.
One type of testing that is often performed is called regression analysis, or sometimes verification testing. Regression analysis involves the selective retesting of a software that has been modified in order to fix known problems. The selective retesting is performed in order to ensure that the identified problems have been fixed, and that no other previously working functional components have failed as a result of the reparations. This type of testing is basically a quality control measure to ensure that the modified code still complies with its specified requirements and that any unmodified code has not been affected by the maintenance activity.
An important feature in regression analysis specifically and in software testing in general is the ability to observe the variable values resulting from the test vectors. Early attempts to observe the variable values of a software and/or the functional components thereof involved manually setting break points and other traps in the source code itself. More recently, software development tools such as Code Composer Studio™ from Texas Instruments and LabVIEW™ from National Instruments include software probes that may be inserted into the code under test. The software probes allow the variables in the code under test to be observed in real-time as the software is executed. These latter solutions, however, are based only on getting the variable values out from the code under test (e.g., so they can be analyzed). They do not allow the variable values to be changed during the execution of the software. In other words, presently existing software probes are only one-way or unidirectional probes in that the data is allowed to flow only from the code under test to the test system. They do not allow the direction of data transfer to be reversed so that data flows from the test system into the code under test.
Accordingly, it would be desirable to provide a way to probe software in a manner such that data may be transferred both out of as well as into the code under test.